Air conditioning system with heating means



y 1967 J. P. MURDOCH 3,320,762

AIR CONDITIONING SYSTEM WITH HEATING MEANS Filed Dec. 8, 1965 FIG. I.

Cam/1'1. ianer Gaol/n2 Tower I C 00 //'n g i'awvr' Plunging Unit FIGS.

228 Conditioner INVENTOR:

JOHN P. MURDOCH ATTYS.

United States Patent 3,320,762 AIR CONDITIONING SYSTEM WITH HEATING MEANS John P. Murdoch, 3630 Haverford Ave., Philadelphia, Pa. 19104 Filed Dec. 8, 1965, Ser. No. 512,362 8 Claims. (Cl. 62-183) The present invention relates to an air conditioning system for use in buildings having refrigerated compartments, equipment and the like, wherein the heat developed from the operation of the refrigeration units is utilized for the purpose of providing sensible heat to other areas of the building. More particularly, the present invention relates to improvements in systems for the control of a coolant of the type shown in my Patent No. 3,186,183 embodying a safety feature to avoid damage to the refrigeration units in the event of failure of certain elements of the system.

In coolant systems of the stated type, a liquid coolant is used as the heat exchange medium in the condensers of the refrigeration units of the refrigerated compartments, equipment, and the like. The liquid coolant, usually water, is normally maintained at the proper temperature for the eflicient functioning of the condensers in one of three ways. In the open system, the coolant is sprayed into a cooling tower and is cooled by evaporation and collected in a sump for recirculation through the condensers. In the closed system, the liquid is pumped through coils in a cooling tower, which coils are cooled by the spraying of water over the coils, the spray Water being cooled by evaporation. In the fresh water system, the water from the condensers is discharged into a drain and fresh water is continuously supplied, the fresh water being at a suitable temperature for the efificient operation of the condensers.

In systems in accordance with the invention of my Patent No. 3,186,183, the sensible heat added to the coolant in the condensers is utilized, for example during winter operation, to add heat to other areas of the building. In accordance with the system shown in said patent, the discharge line from the condensers to the cooling tower or drain is closed and the coolant is lay-passed through a reclaimed heat coil and then to the supply line of the condensers so that the heat added to the coolant in the condensers may be dissipated in the reclaimed heat coil and used to add sensible heat to other areas of the building. It has been found that there is a possibility in systems of this type that the flow through the condensers may be inadvertently restricted or arrested, for example by failure of valving means or blockage of the conduits.

Although control means are provided to reopen the discharge line when the temperature of the coolant flowing through the coil and recycled through the condenser rises above a desirable temperature level, in the event of failure of the flow, such control means may not function. When flow through the condensers is interrupted or restricted, continued operation of the refrigeration unit embodying the condensers may cause the unit to burn out or other wise fail to function, leading to a loss in refrigeration of the refrigerated compartments, equipment, or the like. Systems of this character are especially adapted for use in retail grocery outlets, and failure of the refrigeration equipment may lead to considerable loss in perishable items which must be maintained under refrigeration.

3,320,762 Patented May 23, 1967 With the foregoing in mind, the present invention provides an air conditioning system wherein heat from the coolant in refrigerating units is utilized and further wherein malfunction in the controls or in the system does not interrupt the flow of coolant through the refrigerating units.

More specifically, the present invention provides in a coolant system for use in air-conditioning systems of the stated type employing a reclaimed heat coil, means to insure proper flow of coolant through the refrigerating unit when flow through the reclaimed heat coil is inadvertently arrested or restricted.

All of the objects of the invention are more fully set forth hereinafter with reference to the accompanying drawing wherein:

FIG. 1 is a schematic representation of an air-conditioning system using an open coolant system embodying the present invention;

FIG. 2 is a view similar to FIG. 1 showing a closed system embodying the invention; and

FIG. 3 is a similar view of a fresh water system embodying the present invention.

The present invention provides an air-conditioning systern having a reclaimed heat coil connected in a reclaimed heat loop including the condensers of the refrigeration units between the discharge line and the supply line for the condenser. Energizable means is provided in the loop to selectively cause flow through the reclaimed heat loop instead of the conventional flow through the discharge line. The discharge line has a normally closed valve therein biased to the normally closed position and operable to be displaced to an open position when the pressure in the discharge line rises above a predetermined level whereby when the flow through the loop including the reclaimed heat coil is arrested or restricted, the coolant operates to open the biased valve, thereby opening the discharge line and affording flow of water into the supply line independently of the flow through the loop.

Referring now to the drawing, and particularly FIG. 1 thereof, the air conditioning system is illustrated therein in connection with a market building 10 having at least one conventional refrigeration unit 11 for the compartments and/or display cases, and a substantially conventional air conditioning system including a conditioner 12 and a blower 13 for conditioning the air in the market building 10. The refrigeration unit 11 includes the usual compressors, coils, and condensers with expansion devices therein, said condensers being cooled by a liquid coolant which is supplied thereto by an inlet line 21 and discharged therefrom by an outlet line 22. In the system shown in FIG. 1, the outlet line 22 is connected to a discharge line 26 through a valve 27. The discharge line 26, when the valve 27 is open, discharges the coolant, usually water, into an open cooling tower 24 having a sump 23 at its exit end and a conventional blower 28 which is rendered operative according to the demands of the system. If desired, the sump may be located remotely from the tower. From the sump 23, a supply line 29 feeds the coolant to the inlet of a pumping unit 25 which discharges into the inlet line 21 for the condensers. The pumping unit 25, as shown schematically, comprises a pair of pumps 51 and 52 which are operated alternately in a predetermined cycle by conventional controls (not shown) to control the pressure of the coolant in the inlet line 22 to insure continuous flow of coolant through the refrigerating unit 11.

As shown in my Patent No. 3,186,183, the coolant from the outlet line 22 may by-pass the cooling tower and be caused to flow through a reclaimed heat coil 31 in the conditioner 12. To this end, a branch line 32 is connected to the outlet line 22 upstream of the valve 27 through an energizable means, in the present instance a valve 37. The branch line 32 is connected to the inlet of the reclaimed heat coil 31 and the outlet of the coil 31 is connected by a second branch line'33 to the sump 23, thereby forming a reclaimed heat loop including the coil 31, the pumping unit 25 and the condenser of the refrigeration unit 11. A controller 41 is provided to control the energization'of the valve 37. To this end, a room thermostat 42 is provided within the building When the room thermostat 42 calls for additional heat Within the building 10, a signal is transmitted to the controller which energizes the valve 37 so as to open the branch line 32 to the outlet line 22. Opening the valve 37 causes flow through reclaimed heat loop including the reclaimed heat coil 31 and the branch line 32 and 33 so as to by-pass the flow around the tower 24. When the valve 37 is fully open, the valve 27 is closed so that the entire flow of coolant from the condensor in the unit 11, passes through the reclaimed heat coil 31 to the sump 23. The flow of air through the air conditioning unit 12 normal-1y is sufiicient to reduce the temperature of the coolant in the reclaimed heat coil to a point where it is effective to cool the refrigerant in the condensers of the refrigerating unit 11. In order to insure eflicient operation of the unit embodying the condensers in the event there is insufficient cooling in the reclaimed heat coil 31, a thermostat 43 is mounted in the reclaimed heat loop, in'the present instance in the outlet line 22 to sense the temperature of the coolant flowing through the loop. The position of the thermostat in the loop is not critical, so long as it responds to the temperature of the coolant flowing through the condenser. When the temperature of the coolant in this loop :rises above a desirable level, the thermostat 43 transmits a signal to the controller 41 which over-rides the control of the room thermostat 42 and de-energizes the energizable valve 37 so as to effect closing thereof. Closing the valve 37 opens the valve 27 to cause the coolant to flow through the cooling tower and to thereby lower the temperature of the coolant being fed to the inlet-line 21 to the desirable temperature level.

In accordance with the present invention, the valve 27 is operated automatically by the pressure of the coolant in the outlet line 22. Thus, in the event of malfunction of the system, such as a blockage of the reclaimed heat coil 31 retarding flow through the reclaimed heat loop described above, the pressure in the outlet line 22 increases. In the present instance, the valve 27 is a spring-loaded relief valve which operates automatically when the pressure on the upstream side exceeds a predetermined value, for example the maximum normal pressure in the line 22 when the reclaimed heat loop is func tioning properly. As desired, the valve may open gradually in response to gradual increases in pressure or may open fully in response to any increase in pressure above the preselected pressure level. When the energizable valve 37 is adapted to open gradually, the valves 27 and 37 cooperate to function as a proportioning unit to proportion the fiow between the reclaimed heat loop and the cooling tower. Thus, when the valve 37- is open halfway, the pressure in the outlet line 22 increases to a point to efiect half opening of the valve 27, so that half of the flow may be diverted through the cooling tower 24 and half through the reclaimed heat coil 31 of the air conditioning system. In any event, the use of a valve intermediate the condenser outlet line 22 and the discharge line 26 which is biased to a closed position and operable to be opened by an increase in pressure in the outlet line, serves to insure flow through the condensers of the refrigeration unit 11 at all times when the pumping unit 25 is operating, avoiding any opportunity for the system to inadvertently terminate cooling of the condensers of the refrigeration units and insuring continued operation of the refrigeration units.

The present invention may also be embodied in a closed system, for example as shown in FIG. 2. In this embodiment of the invention, a market building having a refrigerating unit 111 therein, is provided with an air conditioner 112. In this system, the inlet line 121 to the condenser of the unit 111 supplies a liquid coolant, normally water, which is discharged through the outlet line 122. The outline 122 is connected to the exit end of a coil 123 in a cooling tower 124 through a valve 127 and a discharge line 126. The coolant in the coil 123 is cooled either by air alone or by a spray of water which is recirculated from the sump of the cooling tower in a conventional manner. For winter operation, a heater unit is included in the tower to prevent freezing or excessive cooling. The water from the cooling coils 123 is discharged into a supply line 129 which is connected to the condenser inlet line through a pumping unit similar to the pumping unit 25 described above to control the cool-ant pressure in the inlet line to cause flow through the condenser. The pumping unit 125 may alternatively be located in the line 122. A conventional expansion tank 130 is connected to the supply line 129 to relieve the pressure in the system.

A reclaimed heat coil 131 is provided in the conditioner 112 and is connected to the condenser outlet line 122 upstream of the valve 127, by means of a branch line 132. The outlet of the reclaimed heat coil 131 is connected ot the supply line 129. by a second branch line 133, forming a reclaimed heat loop including the coil 131, the pumping unit 125 and the condenser of the refrigeration unit 111. Flow through the reclaimed heat loop is controlled by energizable means, in the present instance a motor valve in the first branch line 132. The motor valve 137 is normally closed and is connected to a controller 141 so as to be energized when the space in the building 110 requires additional. heat, under the control of a thermostat 142 in the building.

Means is provided to sense the temperature of the coolant in the reclaimed heat loop to over-ride the thermostat 142 when the temperature of the coolant is improper. A closed system of this type may require accurate control of the coolant temperature. T 0 this end, a low limit thermostat 143 and a high limit thermostat 144 are provided in the loop, in the present instance in the supply line 129. The thermostats 143 and'144 are connected to the controller and operate to control the valve 137 to maintain the temperature of the coolant in the supply line within the proper range. The cooling tower is likewise controlled in a conventional manner to maintain the coolant temperature in the proper range as it flows through the coil 123.,

In accordance with the invention, the valve 127 is biased to a normally closed position and is operated automatically by the presure in the. condenser outlet line 122 to open when the pressure in the line 122 rises above a preset level. The preset level is normally the maximum pressure in the line 122 when the reclaimed heat loop is functioning properly, so that when the valve 137 is closed, the pressure buildup in the line 122 opens the valve 127 to maintain the proper flow through the condensors of the refrigerating units 111. Thus, in the event of failure of the valve 137 to open, or in the event of restriction of the flow through the coil 131, the valve 127 operates automatically to maintain the necessary flow through the condensers to prevent damage to the refrigerating unit.

The invention is also applicable to a fresh water system such as shown in FIG. 3 of the drawing. In this embodiment of the invention, a building 210 is provided with a conditioner 212 and refrigerating unit 211. The condenser inlet line 221 ;is connected to a fresh water supply line 224 through a pressure regulating valve 229 to control the coolant pressure in the line 221 so as to cause flow through the condenser. The condenser outlet line 222 is connected to a discharge line 226 and drain 228 through a valve 227. The conditioner 212 includes a reclaimed heat coil 231 whose inlet is connected to the mndenser outlet line 222 by a branch line 232 upstream of the valve 227. The outlet of the coil 231 is connected to the condenser inlet line 221 by a second branch line 233, to thereby form a reclaimed heat loop including the coil 231 and the condenser of the refrigeration unit 211. Energizable means is provided to effect flow through the reclaimed heat loop. In the present instance, the energizable means comprises a pumping unit 237 including a check valve 238 operable when energized to cause How in the reclaimed heat loop, including the branch line 232, the reclaimed heat coil 231, the second branch line 233, the condenser inlet line 221, and the outlet line 222. The pumping unit 237 is energized by a controller 241 adapted to receive a signal from a room thermostat 242. The pumping unit 237 may alternatively be located in the branch line 232. To prevent overheating of the condenser, a thermostat 243 is mounted in the loop, in the present instance in condenser outlet line 222, to sense the temperature of the coolant flowing through the condenser. When the temperature of the coolant rises above a desirable level, the thermostat 243 overrides the thermostat 242 and de-energizes the pumping unit 237 to arrest flow through the reclaimed heat coil 231.

In accordance with the invention, the valve 227 is biased to closed position and is operable to be opened by the pressure of the coolant in the condenser outlet line 222, when the pressure exceeds a preset value. The valve 227 is normally set to open when the pressure in the condenser outlet line 222 exceeds the maximum pressure in the line 222 when the reclaimed heat loop is functioning properly. When the pumping unit 237 is operative, the unit 237 in conjunction with the valve 229 maintains the pressure in the outlet line 222 below the pressure at which the valve 227 opens so that the valve 227 is maintained closed when the system is functioning properly. In the event of arrest or malfunction of the pumping unit 237 or blockage in the reclaimed heat coil 231 causing an arresting or restriction of the flow therethrough, the pressure in the outlet line 222 increases above the pressure to which the valve 227 is set so as to cause the valve 227 to open permitting flow of fresh water through the con denser in the unit 211 to insure proper operation thereof.

Thus, the present invention provides an air conditioning system embodying a reclaimed heat coil-z wherein an automatic valve is provided intermediate the condenser outlet line and the discharge line. The valve is biased to a normally closed position and is operable by the coolant pressure in the condenser outlet line, to an open position affording continuous flow through the condenser of the refrigeration unit in the event of inadvertent failure or restriction in the flow through the reclaimed heat coil. In this manner, flow of coolant through the condenser is assured at all times.

While particular embodiments of the present invention has been herein illustrated and described, it is not intended to limit the invention to such disclosure, but changes and modifications may be made therein and thereto within the scope of the following claims.

I claim:

1. In a coolant system for an air conditioning system for use in buildings having refrigerated compartments, equipment, and the like therein, said air conditioning system comprising a conditioner for the air in said building and a blower for discharging the conditioned air into said building, said refrigerated compartments, equipment, and the like having at least one refrigerating unit embodying a condenser operable to be cooled by a liquid coolant, an inlet line to supply liquid coolant to said unit,

and an outlet line to discharge the liquid coolant from said unit; said coolant system including a discharge line, a valve intermediate said outlet line and said discharge line, pressure control means to maintain pressure in said liquid coolant in said inlet line to cause flow of coolant through said condenser, a first branch line connected to said outlet line, a second branch line connected to said inlet line, a reclaimed heat coil in said air conditioning system adjacent said blower in the path of the air being discharged into the building by said blower, said coil being connected at one end of said first branch line and connected at the other end to said second branch line to form a reclaimed heat loop including said inlet line, said refrigeration unit, said outlet line, said first branch line, said coil, and said second branch line; energizable means in said loop downstream of said outlet line and upstream of said inlet line operable when energized to afford flow through said loop and operable when tie-energized to prevent fiow through said loop, a controller operable to energize and de-energize said energizable means, and thermostat means operatively connected to said controller to control energization of said energizable means to thereby control the flow of coolant through said loop, the improvement wherein said valve is biased toward a closed position and responsive to the pressure of the coolant in said outlet line to open against said bias when the flow through said loop is restricted.

2. A coolant system according to claim 1 wherein said valve is opened when the pressure in said outlet line rises above the normal pressure therein when said loop is functioning properly.

3. The system according to claim 1 including a cooling tower having entrance and exit ends, said discharge line being connected to said entrance end and including a supply line connected to said exit end wherein said pressure control means comprises a pumping unit connected intermediate said supply line and said discharge line, and said energizable means comprises an energizable valve intermediate said outlet line and said first branch line,

4. A system according to claim 3 wherein said system is an open system, said cooling tower having spray means at the entrance end and sump means at the exit end to cool the coolant by evaporative action.

5. A system according to claim 3 wherein said system is a closed system, said cooling tower comprising a closed coil having one end connected to the entrance end and the other end connected to the exit end and including spray means for indirect heat exchange with the liquid coolant in said coil.

6. A system according to claim 1 wherein said discharge line is connected to a drain and said inlet line is connected to a supply line comprising source of fresh water, said pressure control means comprising a pressure control valve intermediate said supply line and said inlet line, said energizable means in said reclaimed heat loop comprising a pump operable when energized to maintain the pressure of the coolant in said inlet line at least at the pressure of said pressure control valve, the suction pressure of said pump being below the pressure required to overcome the bias of said biased valve.

7. A system according to claim 1 wherein said thermostat means includes a thermostat in said building responsive to the air temperature in said building and operable to energize said energizable means when the air temperature in said building falls below a predetermined level and including a second thermostat responsive to the temperature of the coolant flowing through said reclaimed heat loop, said second thermostat being operable when the coolant in said loop exceeds a predetermined desirable temperature level to interrupt energization of said energizable means and to thereby restrict the flow of coolant through said loop when the temperature of said coolant rises above said desirable temperature level.

8. A system according to claim 7 wherein said cool- '7 8 ant system includes a third thermostat responsive to the References Cited by the Examiner temperature of the coolant flowing throughsaid loop, UNITED STATES PATENTS said third thermostat being operable when the coolant temperature in said loop falls below a predetermined 2,715,320 8/1955 Wnght 62fl183 X minimum temperature level to operate said controller ;;2 i:;-

to restrict the flow of coolant through said loop and effect flow through said discharge line until said temperature rises above said predetermined minimum. MEYER PERLIN" Pnmary Examme-r' 

1. IN A COOLANT SYSTEM FOR AN AIR CONDITIONING SYSTEM FOR USE IN BUILDINGS HAVING REFRIGERATED COMPARTMENTS, EQUIPMENT, AND THE LIKE THEREIN, SAID AIR CONDITIONING SYSTEM COMPRISING A CONDITIONER FOR THE AIR IN SAID BUILDING AND A BLOWER FOR DISCHARGING THE CONDITIONED AIR INTO SAID BUILDING, SAID REFRIGERATED COMPARTMENTS, EQUIPMENT, AND THE LIKE HAVING AT LEAST ONE REFRIGERATING UNIT EMBODYING A CONDENSER OPERABLE TO BE COOLED BY A LIQUID COOLANT, AN INLET LINE TO SUPPLY LIQUID COOLANT TO SAID UNIT, AND AN OUTLET LINE TO DISCHARGE THE LIQUID COOLANT FROM SAID UNIT; SAID COOLANT SYSTEM INCLUDING A DISCHARGE LINE, A VALVE INTERMEDIATE SAID OUTLET LINE AND SAID DISCHARGE LINE, PRESSURE CONTROL MEANS TO MAINTAIN PRESSURE IN SAID LIQUID COOLANT IN SAID INLET LINE TO CAUSE FLOW OF COOLANT THROUGH SAID CONDENSER, A FIRST BRANCH LINE CONNECTED TO SAID OUTLET LINE, A SECOND BRANCH LINE CONNECTED TO SAID INLET LINE, A RECLAIMED HEAT COIL IN SAID AIR CONDITIONING SYSTEM ADJACENT SAID BLOWER IN THE PATH OF THE AIR BEING DISCHARGED INTO THE BUILDING BY SAID BLOWER, SAID COIL BEING CONNECTED AT ONE END OF SAID FIRST BRANCH LINE AND 